Patent GB-911758-A (GB)
Title: Improvements in or relating to remote control handling apparatus for sealing pipes with plug and seal devices
Inventor: DUFFIN GEOFFREY WILLIAM
IPC: G21C19/115
Filed: 1958-12-10
Abstract: 911,758. Reactors. ROLLS-ROYCE Ltd. Nov. 30, 1959 [Dec. 10, 1958], No. 39917/58. Class 39 (4). In order to seal by remote control a standpipe of a reactor there is provided a handling apparatus by which a plug and seal device may be inserted and locked in the standpipe. The plug and seal device 11 comprises a body 13 having apertures 16 receiving looking balls 17 which are retained when the device 11 is removed from the standpipe 10 by a sleeve 15 slidable and captive on the body, the sleeve being biased to the Fig. 1 position by springs 14. A locking sleeve 18 slidable on a tubular portion 13b of the body 13 moves downwardly relative to the body by a spring 19 to move the balls 17 into an annular recess 10b in the standpipe when the body 13 has been moved down to the Fig. 2 position whereby the plug is locked to the standpipe. A stem 22 slidable within the portion 13b carries a sealing disc 21 which is moved from the non-sealing position, Fig. 1, to the sealing position, Fig. 2, by upward movement of the stem which causes the disc to engage the lower end of the body 13 and be flattened. In this position of the stem 22 a groove 22b in the stem is out of alignment with apertures 13d in the tubular body portion 13b whereby locking balls 23 are held in a groove 18h in the sleeve 18 so that the sleeve is locked to the body 13. The upper end of the sleeve 18 has a cam surface 18g leading to an annular shoulder 18f and the stem 22 has a mushroom-shaped head 22c. The handling apparatus 12 comprises a cylindrical latch carrier 25 having three slots 25b, each receiving a latch 26 pivoted at 27, the latch movement being limited by a pin 28 and slot 26c, a spring-loaded roller 29 tending to hold the latch in either of its limiting positions. Three further slots 25c in the carrier 25 each receive a lever 39 having a slot 41 engaging a pivot-pin 40 mounted on the carrier, each lever being also pivoted to the lower end of a corresponding bracket 38 secured to a cylindrical body 30. The body 30 slidably receives at its lower end a projection 25d of the carrier 25 and also receives a load input member 31 biased by a main spring 32 which abuts a plate 33 secured to the body of three studs 35. A shroud 37 mounted on the body 30 by a ball-bearing 36 has slots 37a to accommodate the brackets 38 and further slots 37b which in the position shown in Fig. 5 are opposite the latches 26; however, the shroud may be rotated so that the brackets 38 occupy the opposite sides of the slots 37a and it then prevents the latches from moving out to their full extent. A disc 43 guided on the studs 35 has a spring-loaded plunger 44 engaging a helical slot 46 in the shroud (Fig. 3) so that on compression of the spring 32, Fig. 2, by the member 31 a shoulder 31b lifts the disc 43 to rotate the shroud 37. The member 31 is attached to a hoist cable 42 and the shroud is returned to its original position, Figs. 1, 5, by lifting the handling apparatus so that the disc 43 engages a fixed ring 47. Operation.-To pick up a device 11 prior to its insertion into a standpipe 10 the apparatus 12 is lowered so that the carrier 25 enters the sleeve 18 and the radially outer camming surfaces 26b on the latches 26 engage the cam surfaces 18g whereby the latches are swung inwardly and the radially inner shoulders 26a on the latches are below the head 22c, Fig. 1. The device 11 is then lifted by the cable 42 into alignment with the standpipe and the device is lowered whereby springs 14 are compressed permitting spring 19 to move the balls 17 by the sleeve 18 into the recess 10b, also the balls 23 leave the groove 22b so that the stem 22 is free to move. The apparatus 12 is now raised so that the disc 21 engages the body 13 and is flattened, and the parts then occupy the Fig. 2 position. The tension in the cable 42 necessary for flattening the disc 21 is sufficient to cause compression of the main spring 32 whereby the shroud 37 is rotated so that.. the slots 37b are not in alignment with the latches 26. To release the apparatus 12 from the device 11 the apparatus is lowered so that the radially inner camming surfaces 26b rub on the head 22c, causing the latches 26 to move outwards, the degree of outward movement being limited by the shroud. In this intermediate position of the latches the shoulders 26a are clear of both the head 22c and the shoulder 18f so that the apparatus 12 may be removed, the disc 43 being brought into engagement with the ring 47 to restore the shroud. To remove the device 11 from the standpipe the apparatus 12 is lowered so that the latches 26 are moved to their full outer extent by the head 22c and the radially outer shoulders 26a engage the shoulder 18f, Fig. 6; also, the spherical ends 39a of the levers 39 engage the head 22c so that the levers move about the pivots 40 and the body 30 is moved down relatively to the carrier 25. A tension is now applied to the cable 42, insufficient to compress the spring 32, whereby a load is transmitted to the stem 22 through the brackets 38 and levers 39 and the disc 21 is released from its sealing position. The groove 22b is now in alignment with the apertures 13d and the levers 39 engage the upper edges of the slots 25c, the rooking of the levers causing the body 30 to move away from the carrier and the load is transmitted from the carrier 25 to the sleeve 18 through the engagement of the shoulders 26a with the shoulder 18g. The sleeve 18 is raised compressing the spring 19 and the sleeve 15 moves to retain the balls 17 in the apertures 16, the load being transferred from the sleeve 18 to the body 13 upon engagement of a shoulder 18d with an abutment 20 secured to the portion 13b.